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Worksheetsaio ch.6.Chemical Coordination in Plants
Total questions: 75
Worksheet time: 38mins
Which of the following is a plant hormone?
Adrenaline
Cytokinin
Glucagon
Oxytocin
Plant hormones, which promote growth are
gibberellins and ethylene
auxin and ethylene
auxin, cytokinin and gibberellins
cytokinin and abscisic acid
Auxin inhibits the growth of
apical buds
lateral axillary buds
root on stem cuttings
parthenocarpic development of fruits
A plant hormone responsible for inducing morphogenesis during plant tissue culture is
ethylene
gibberellin
cytokinin
abscisic acid
High auxin to cytokinin ratio favours the
root development
shoot development
formation of undifferentiated cells
None of the above
The plant hormone triggering the fall of mature leaves and fruits from plants is
auxin
gibberellin
abscisic acid
kinetin
The stress hormone is
auxin
cytokinin
ethylene
abscisic acid
Both ethylene and ABA are responsible for
promoting abscission of leaves and fruits
inducing dormancy of seeds
stimulation of apical dominance
ripening of fruits
A plant's response to light is known as
geotropism
hydrotropism
photonasty
phototropism
Which one of the following plant hormones is responsible for phototropism in plants?
Cytokinin
Gibberellins
Ethylene
Auxin
The roots of a plant are
positively phototropic but negatively geotropic
positively geotropic but negatively phototropic
negatively hydrotropic but positively phototropic
positively phototropic but negatively geotropic
When roots of a plant always move towards water, even if it means going against the pull of gravity. This indicates
geotropism
negative geotropism
hydrotropism
positive geotropism
The climbing organs of plants like tendrils grow towards any support which they come in contact of and wind around them for support. This is an example of
thigmotropism
nastic movements
geotropism
chemotropism
Which of the following is an example of a nastic movement, not a tropism?
Growth of a pollen tube towards a sugary substance
Folding up of the leaves of Mimosa pudica when touched
Twining of tendrils around a support
The downward growth of a root
Which of the following is a naturally occurring auxin in plants?
Gibberellin
Cytokinin
IAA (Indole-3-acetic acid)
Ethylene
Which hormone helps in breaking seed and bud dormancy?
Auxin
Gibberellins
ABA
Ethylene
A high ratio of which of the following promotes shoot development?
Auxin to Cytokinin
Cytokinin to Auxin
Gibberellin to Auxin
ABA to Gibberellin
Ethylene, a plant hormone that causes fruit ripening, exists in what form?
Solid
Liquid
Gaseous
Plasma
Stomatal closure is induced by which hormone?
ABA (Abscisic acid)
Auxin
Cytokinin
Gibberellin
The stem and leaves of a plant exhibit which tropic movement?
Positively phototropic
Negatively phototropic
Positively geotropic
Negatively geotropic
The downward growth of a plant's root is an example of what?
Negative geotropism
Positive phototropism
Positive geotropism
Negative phototropism
Which of the following is the movement of a plant or its part in response to a chemical stimulus called?
Thigmotropism
Phototropism
Geotropism
Chemotropism
Is the statement "Ascorbic acid is a naturally occurring plant hormone" true or false?
True
False
Is the statement "Seed dormancy is due to abscisic acid" true or false?
True
False
The bending of a plant stem towards light is caused by which hormone?
Cytokinin
Auxin
Gibberellin
Ethylene
The stimulus in thigmotropism is which of the following?
Light
Gravity
Touch
Water
Which function corresponds to the plant hormone IAA (Auxin)?
Elongation of dwarfs
Flowering in pineapple
Cell division
Cell wall elongation
Which function corresponds to the plant hormone Cytokinin?
Elongation of dwarfs
Flowering in pineapple
Cell division
Cell wall elongation
Which function corresponds to the plant hormone Gibberellic acid?
Elongation of dwarfs
Flowering in pineapple
Cell division
Cell wall elongation
What type of tropism is a plant's response to light?
Thigmotropism
Phototropism
Geotropism
Chemotropism
What type of tropism is a plant's response to touch?
Thigmotropism
Phototropism
Geotropism
Chemotropism
What type of tropism is a plant's response to gravity?
Thigmotropism
Phototropism
Geotropism
Chemotropism
What type of tropism is a plant's response to a sugar or chemical?
Thigmotropism
Phototropism
Geotropism
Chemotropism
Which of the following is a primary function of the cytokinin hormone in plants?
Cell division
Growth regulation
Stress response
Nutrient transport
Which hormone is known to delay the falling of leaves?
Gibberellin
Cytokinin
Auxin
Abscisic acid
Which hormone is known to prevent or delay the ageing of plant parts?
Gibberellin
Cytokinin
Auxin
Abscisic acid
Which plant hormone retards growth and makes seeds dormant, especially during dry seasons?
Auxin
Gibberellin
Cytokinin
Abscisic acid
Which plant hormone is primarily responsible for the elongation of cells?
Auxin
Gibberellin
Cytokinin
Abscisic acid
Which plant hormone is primarily responsible for the growth of the stem?
Auxin
Gibberellin
Cytokinin
Abscisic acid
Which plant hormone is primarily responsible for promoting cell division?
Auxin
Gibberellin
Cytokinin
Abscisic acid
Which plant hormone is responsible for the falling of senescent (old) leaves?
Auxin
Gibberellin
Cytokinin
Abscisic acid
A young green plant receives sunlight from one direction only. What will happen to its shoot and roots?
The shoot and roots will both bend towards the light.
The shoot will bend towards the light, and the roots will bend away from it.
The shoot and roots will both bend away from the light.
The shoot will bend away from the light, and the roots will bend towards it.
Why are roots known as positively geotropic?
They grow away from the Earth's gravity.
They grow towards the Earth's gravity.
They grow towards the light.
They grow away from the light.
Which of the following are two types of tropic movements?
Geotropism and Phototropism
Geotropism and Nastic movement
Chemotropism and Thigmotropism
Both (a) and (c)
In what way are tropic movements different from other types of movements?
They are nondirectional.
They are directional with respect to the stimulus.
They are always rapid.
They are independent of any stimulus.
What is the technical term for the movement of a plant part towards a chemical substance?
Geotropism
Phototropism
Hydrotropism
Chemotropism
Why are electrical-chemical signals not considered an efficient means of communication in plants?
Plants lack a nervous system and circulatory system for hormone conduction.
Electrical signals are too slow in plants.
Plants do not produce chemical signals.
Plant cells cannot transmit electrical signals.
How are control and coordination carried out in plants?
Through a nervous system
Through electrical signals only
By chemical substances called phytohormones
By muscular movements
What are two important functions of auxins?
Promote cell elongation and root formation
Promote fruit ripening and flowering
Promote cell division and seed dormancy
Promote flowering and leaf fall
How does spraying sugarcane plants with gibberellins increase the yield of sugar?
It increases the sweetness of the existing sugar.
It increases the length of the internodes, leading to more sugar production.
It makes the plant produce more leaves.
It increases the number of sugarcane plants.
In an experiment, a callus did not grow until a substance was added. This substance was a mixture of auxin and cytokinin. What is the role of cytokinin in this experiment?
It stimulates the growth of plant tissues.
It inhibits the growth of the callus.
It provides nutrients to the callus.
It causes the callus to produce roots.
Which plant growth regulator is used to induce rooting in a twig?
Auxins
Ethylene
Cytokinin
Gibberellin
Which plant growth regulator is used to quickly ripen a fruit?
Auxins
Ethylene
Cytokinin
Gibberellin
Which plant growth regulator is used to induce growth in axillary buds?
Auxins
Ethylene
Cytokinin
Gibberellin
Where are auxins synthesized in a plant?
Apical buds and roots
In green fruits and seeds
In all parts of the plant
Only in the leaves
What is a primary function of gibberellin?
Promotes cell elongation
Promotes cell division
Breaks seed and bud dormancy
Promotes fruit ripening
Which plant hormone is synthesized in green fruits and seeds at the beginning of the wintering season?
Auxins
Gibberellin
Cytokinin
Ethylene
By keeping a potted plant in a dark room by the side of an open window, what phenomenon is demonstrated?
Negative phototropism
Positive geotropism
Positive phototropism
Thigmotropism
When a plant is exposed to unidirectional light, which hormone facilitates the bending of the shoot towards the light source?
Cytokinin
Gibberellin
Auxin
Abscisic acid
The opening of a flower is an example of which type of movement?
Tropic movement
Nastic movement
Geotropism
Phototropism
The downward movement of roots is an example of which tropic movement?
Phototropism
Geotropism
Thigmotropism
Hydrotropism
The movement of shoots towards light is an example of which tropic movement?
Phototropism
Geotropism
Thigmotropism
Hydrotropism
The twirling of a tendril around a support is an example of which tropic movement?
Phototropism
Geotropism
Thigmotropism
Hydrotropism
Which of the following is a key function of Cytokinin?
Inhibits growth
Causes dormancy of seeds
Causes stomatal closure
Promotes cell division and delays aging
What is chemotropism?
The growth of a plant in response to a light stimulus.
The growth of a plant in response to a chemical stimulus.
The growth of a plant in response to gravity.
The growth of a plant in response to touch.
Which of the following are the five main natural plant growth regulators?
Auxins, Gibberellins, Ethylene, Cytokinins, and ABA
Nitrogen, Phosphorus, Potassium, Auxins, and Gibberellins
IAA, NAA, 2,4-D, Ethylene, and ABA
Auxins, Gibberellins, Chlorophyll, Cytokinins, and ABA
Which of the following is a physiological function of auxins?
Inducing dormancy in seeds
Ripening of fruits
Initiating rooting in stem cuttings
Causing stomatal closure
Which of the following is an agricultural application of auxins?
Used as a fertilizer to increase nutrient content
Used to promote rooting in stem cuttings
Used to delay fruit ripening
Used to induce flowering
Where are gibberellins primarily produced in plants?
In the flowers and fruits
In the embryos, roots, and young leaves near the shoot tip
Only in the stem and mature leaves
In the bark and woody tissues
What is a primary function of gibberellins?
To promote cell division
To delay senescence (aging) in plants
To cause stomatal closure
To inhibit stem elongation
Why was the hormone "gibberellin" so named?
It was discovered by a scientist named Gibberell.
It is primarily found in the gibberellin plant.
It was named after the fungus, Gibberella fujikuroi, from which it was sourced.
It is a combination of the Latin words for "growth" and "hormone."
Besides increasing sugarcane yield, what is another agricultural use of gibberellins?
To promote weed growth
To inhibit root development
To promote seed germination
To cause leaves to fall
Which plant hormone is present in greater concentration in the areas of rapid cell division?
Auxin
Gibberellin
Cytokinin
Abscisic acid
Which statement accurately describes a positive and negative role of ethylene?
Positive: Promotes senescence; Negative: Breaks seed dormancy.
Positive: Breaks seed dormancy; Negative: Promotes senescence and abscission of leaves.
Positive: Promotes flowering; Negative: Initiates germination.
Positive: Promotes root growth; Negative: Causes fruit to ripen.
Why do growth-inhibiting hormones become important for plant survival in adverse conditions like harsh winters?
They encourage rapid growth to escape the cold.
They help the plant become dormant until conditions are favorable again.
They increase water absorption from frozen soil.
They promote flowering to ensure reproduction before the plant dies.
